The invention relates to a data converter for a pulse radar apparatus provided with a transmitter and receiver unit; a video extractor connected thereto for obtaining, from the video signals supplied to the video extractor, digitized plotting data consisting of radar target data; a plot processor for determining the track positions with the associated digital data from the plotting data obtained in consecutive antenna revolutions; and a display system for presenting both the video signals from the transmitter and receiver unit and the track positions with the associated digital data.
Thus from the video signals of the transmitter and receiver unit, i.e. the real-time raw video, various digitized plotting data can be derived in the video extractor, including the polar coordinates of the target centroid, the number of hits detected when the radar beam illuminates the target, and the target echo signal strength. From the plotting data obtained in consecutive antenna revolutions the plot processor determines the target course and velocity, i.e. the track formation, to be able to predict future target positions or track positions. The plot processor supplies the track positions to a display for presentation in the form of symbols and labels, which may contain the target velocity, course and track number. For the sake of brevity, the data from the plot processor is denoted synthetic video. The real-time raw video is displayed during the listening time of the transmitter and receiver unit; this permits the synthetic video to be displayed during the interval between the end of a listening time and the start of a following listening time. In many cases, however, the time required to display synthetic video is much greater than the time available for this. It is true that the synthetic video could be displayed during the time available for the display of the real-time raw vido, but this would result in a loss of radar information. The present invention has therefore for its object to overcome this disadvantage.